But Mr Ghazali is not Madam Khatijah's only child who needs special care and attention.

Her other son, 15-year-old Akif, was born with intellectual disability.

His behaviour fluctuates from being hyperactive to aggressive, and he goes through a specialised programme at the Movement for the Intellectually Disabled of Singapore school in Margaret Drive.

HYPERACTIVE

Although not as dependent as his older brother, Akif's condition causes him to be hyperactive and susceptible to the influence of others.

Madam Khatijah said: "Akif can do basic tasks himself, but I have to be there to calm him down and make sure he does not follow strangers."

Most of Madam Khatijah's days involve getting her children ready for school and making sure their needs are met.

In the evenings, when people are heading home from work, she travels to her workplace at Tractor Road, near Boon Lay.

"Sometimes I fall asleep on the bus to work," she said.

She gets home from work at about 3am and only then does she finally get to rest.

She wakes up at 6am to get Mr Ghazali ready for school.

In addition to caring for both her children, Madam Khatijah also supports her parents, who are in their 60s. All five of them share a four-room HDB flat in Jurong West.

In 2007, Madam Khatijah also worked on weekends, as a dishwasher at a hotel, for the extra income.

But it proved to be too much, so she left the job after a year.

As she blinked back tears, she said: "I was over-exerting myself. Holding down two jobs on top of taking care of my kids was beyond my limits."

About four months ago, Mr Ghazali's condition started getting worse and his violent episodes became more frequent.

Madam Khatijah had to stop working temporarily to provide round-the-clock care for her him, following him to school every day to ensure he remained calm.

But even without work, she does not get much sleep. The constant care that Mr Ghazali needs keeps her up and she ends up sleeping only at about 1am.

But Madam Khatijah does not see it as a burden.

"As long as either of them need me, I'll be here, even if it means not working and sacrificing sleep," she said.

"My children are a gift to me. I love them so much."

The Ministry of Social and Family Development (MSF) has been helping Mdm Khatijah and her children. In May 2015, Mdm Khatijah left her employment to become full time caregiver. Since then, they have been receiving monthly financial assistance from ComCare. Mdm Khatijah’s children are also supported by various help agencies for their medical and educational needs.

Sleepless in Singapore

Singaporeans are getting the least sleep, as revealed in a study by the University of Michigan.

In the study, which involved more than 6,000 people across 100 countries, Singapore tied for last place with Japan with the average amount of sleep at 7 hours 24 minutes.

In contrast, the Dutch are asleep the most with an average of 8 hours 12 minutes.

The difference of 48 minutes might seem small but the researchers said in their study even 30 minutes of sleep can have significant effects on cognitive function and health.

According to the director of the Sleep Disorders Unit at Singapore General Hospital, Dr Toh Song Tar, Singaporeans do not sleep enough because they are "hardworking".

He told The New Paper: "To get ahead in life and be successful, people work hard and sleep is conveniently sacrificed to meet deadlines and be more productive."

There are also those who think they do not need much sleep because they feel rested on just a few hours of sleep a night.

AFFECTED

But Dr Chong disagrees: "Their performance is likely affected without themselves being aware.

"Research shows that people who sleep so little over many nights don't perform complex mental tasks as well as those who get closer to seven hours of sleep a night."

Sacrificing sleep comes at a huge cost.

Dr Toh said the effects of sleep deprivation are multi-fold, affecting one's brain functions and interfering with decision making and focus.

Their immunity, digestive, respiratory, digestive and cardiovascular systems could also be affected.

"The effects of sleep deprivation are accumulative and often the health consequences manifest only later in life," said Dr Toh.

Dr Chong added that sleepiness can also cause clinical depression, weight gain and even an impaired sex drive.

He said: "Sleep is vital to our health and our sense of well being.

"In an increasingly connected cosmopolitan world, people are getting less sleep as well as poorer quality of sleep."

Her typical day

6am: Madam Khatijah Mohamed Shah wakes up to help her son Ghazali, 19, get ready for school.

7.20am: Transport for Mr Ghazali to Eden School in Bukit Batok arrives.

8am to 10am: Mr Ghazali is in school. When he has bad behavioural problems, she keeps him company and waits for him at school. Or she does household chores or goes to the supermarket.

10.30am: Mr Ghazali is home from school. Madam Khatijah starts to help her son Akif, 15, get ready for his school day, at the Movement for the Intellectually Disabled of Singapore school in Margaret Drive. 11am: Akif's transport to school arrives.

11.15am to noon: Madam Khatijah cooks for her family and feeds Mr Ghazali.

Noon to 2pm: Madam Khatijah does household chores.

2.30pm: She gives Mr Ghazali a shower.

3pm: She gets ready for work.

4pm: She takes public transport to her workplace at Tractor Road, near Boon Lay.

5pm to 2am: Madam Khatijah works.

2.30am: She reaches home and washes up.

3am: She is finally able to sleep.

Do you get enough sleep?

The New Paper asked 100 people if they thought they were getting enough sleep each night. Among those who said 'no', about one in three confessed to choosing to sleep late, preferring to spend time on their devices or entertainment

YES

45%

I prioritise sleep because I've realised how important it is to my physical and mental well-being.

Name Miss Sinéad Tan Age 19 Occupation Student Average hours of sleep 10

I try to finish all my work before 10pm so that I can get enough sleep.